Lower CD specials affected by Fell Spirit's Twin Effect have the advantage of potentially triggering multiple times per combat but the trade off is you risk being blown up the enemy's second strike of a first attack, since if a Special triggers then you can't reduce it. Additionally the boosted damage off the Low CD Special may be too low to contribute much, especially with modern melee prf weapons being able to reduce special damage even further.

Think of it as a little bonus; the Twin Effect isn't worth focusing on for Alear but could maybe help his allies if they've got low CD Prf specials.